Humpback whale ‘protects’ diver from lurking tiger shark

Whales have always inspired awe in us human folk with their majesty and sheer size, but there may be another reason for us to love humpbacks.

Because it looks like these gentle giants are also heroes of the deep.

Marine biologist Nan Hauser claims a humpback whale protected her from a tiger shark during a dive, believing the massive underwater mammal kept her under its flipper to steer her to safety.

And the footage is amazing.

"I wasn't sure what the whale was up to when he approached me, and it didn't stop pushing me around for over 10 minutes," she said.

"It seemed like hours.

"I was a bit bruised up.

"I've spent 28 years underwater with whales, and have never had a whale so tactile and so insistent on putting me on his head, or belly, or back, or, most of all, trying to tuck me under his huge pectoral fin."

No one is entirely sure why humpbacks get involved in beefs that don't involve their species, but Pitman told Science journo Erik Stokstad he reckons they have simple rule when it comes to orcas.

"When you hear a killer whale attack, go break it up," he said.

But while this may be interpreted as a general "stuff you" to the killer whales, protecting a human from a shark is a completely different.

And in a 2016 study about whale rescue missions, Pitman and his fellow researchers noted something that sounds like humpbacks might just be a bunch of nice guys who like to help out their fellow mammal.

"There was no apparent benefit to humpbacks continuing to interfere when other species were being attacked," the report says.

"Interspecific altruism, even if unintentional, could not be ruled out."